/Engine/Plugins/Online/OnlineServicesEOS/Source/Public/Online/SocialEOS.h
void OnEOSFriendsUpdate ( [FAccountId](API\Runtime\CoreOnline\Online\FAccountId) LocalAccountId, [FAccountId](API\Runtime\CoreOnline\Online\FAccountId) FriendAccountId, EOS_EFriendsStatus PreviousStatus, EOS_EFriendsStatus CurrentStatus )